Method for producing a contactless chip card and chip card produced according to said method

ABSTRACT

The invention relates to a method for producing a transponder, especially a contactless chip card ( 1 ) comprising at least one electronic component (chip module  2 ) and at least one antenna ( 3 ); the at least one electronic chip component ( 2 ) being disposed on a non-conducting substrate that serves as a support for the component. The at least one antenna is also disposed on a non-conducting substrate, the at least one electronic component ( 2 ) being applied to a first substrate and the antenna ( 3 ) on a second substrate. The entire circuit ( 1 ) is then produced by joining the individual substrates so that they are correctly positioned relative to each other. The components ( 2, 3 ) are contacted once the different substrates have been joint by means of auxiliary materials such as solder or glue, or without auxiliary materials by microwelding. The non-conducting substrates form a base card body.

RELATED DOCUMENTS

[0001] This patent application is a continuation-in-part application ofthe international patent application PCT/DE02/00949, published asWO-02/077918 A2, designated for the US, which document is fullyincorporated by reference.

TECHNICAL FIELD OF THE INVENTION

[0002] The present invention relates to a method for making atransponder unit with at least one chip and an antenna, in particular,for making a contactless chip card and a transponder unit according tosaid method.

BACKGROUND OF THE INVENTION APPLICATION DESCRIPTION OF THE PRIOR ART

[0003] Contactless chip cards, in the simplest case, comprise twoelectrical components, namely, a chip module and an electricallyconductive antenna connected with the chip module. In complexembodiments, further components, such as, for example, furthermicrochips for data storage, optical displays, batteries, etc., can beintegrated in the chip card. These electronic components are mounted onan electrically non-conductive base substrate, which typically comprisesplastic, is built-into the card, and thus forms a component of the card.With methods known, the chips are processed in part when not insulated,that is, the silicon chip is not accommodated additionally in a housing.In part, on the other hand, the silicon chips, however, are previouslybuilt into a corresponding housing. The housed chip is then generallydesignated as a chip module. Subsequently, with the term “chips”,unhoused as well as housed varieties are meant. Since the cardmanufacture takes place, in practice, in a multiple slit-up manner,multiple transponder units are arranged on a base substrate. Thearrangement takes place in a uniform, screen-type arrangement, wherebyarrangements of approximately 3×8, or 6×6 are the common size used.

[0004] As the closest state of the art, a method for arranging atransponder unit having at least one chip and a wire coil on a substrateis known from DE 44 10 732 C2. With the method proposed there for makinga contactless chip card, a single substrate layer is used in order buildthe various components thereon. In this manner, the antenna is mountedas the first component on the substrate, as with all other knownmethods. Thus, three different methods must be distinguished, namely,the etching method, the printing method and the wire-laying method. Withetching methods, the base substrate is coated over its entire surfacewith copper. In a following photolithography process, the coil isrepresented and the excess copper etched off. With printing methods, thecoil contour is imprinted by means of electrically conductive tints orpastes. In practice, screen printing methods are used. With wire-layingmethods, electrically conductive wire is mounted along the coil contouron a substrate and there, attached spot-wise, or along the completecontour onto this.

[0005] With methods known, like the known method of DE 44 10 732, inwhich only a single substrate layer is used, the next step is mountingthe chip module and the further electronic components, whereby with allknown methods, the components are mounted onto the same substrate. Themounting of the components takes place, such that the contact surface ofthe components is congruent with the contact surface of the previouslymounted components. Mounting of the components takes place sequentially.Next, the electrical contact of the components takes place. In thisregard, the contact surfaces of the individual components are connectedwith one another. The following processes are used: solders,electrically conductive adhesion, and TC bonds, which is also calledmicro-welding. With solders, supplementary solder material is appliedbetween the connection points of the components and after the componentassembly, thermally remelted. With conductive adhesion, an electricallyconductive adhesive is applied additionally between the components,which is hardened after the component assembly. The hardening takesplace in practice under the effect of temperature or UV light. With TCbonds, the contact takes place without additional application of contactmaterial. In this regard, the two contact materials are welded with oneanother by means of a temporary impact of heat.

[0006] The known methods, in particular, the method according to DE 4410 732, however, is connected with disadvantages, whereby as a firstdisadvantage, the rate of yield must be named. When a not implausibleerror occurs, namely with the second step of mounting the chip onto thecommon substrate, the entire previously made product of the method isunusable, a disadvantage that is overcome with the present invention. Inaddition, the method according to DE 44 10 732 is associated with thedisadvantage of a low degree of modularity, since the substrate impactedwith the coil and chip an only be made as a whole, that is, as a unitaryproduct of a modular manufacture, it is not accessible, or is only verydifficultly accessible.

OBJECT OF THE INVENTION

[0007] The noted disadvantages of a method for producing a transponderunit with at least one chip and an antenna, in particular, for producinga contactless chip card are overcome by the present invention.

SUMMARY OF THE INVENTION

[0008] The invention solves the problem by a method for producing atransponder or contactless chip card, said transponder or contactlesschip comprises a first non-conductive substrate and a secondnon-conductive substrate, an electronic component and an antenna, saidfirst and said second non-conductive substrate having essentially thesame outer boundaries, said method comprises the steps of arranging saidelectronic component on said first non-conductive substrate serving as acomponent support, arranging said antenna on said second non-conductivesubstrate, and thereafter, by means of correct and accurate positionalassembling the individual substrates, producing the total switchingmechanism by laminating the substrate layers using heat and therebymelting of the various substrate layers so that a hermetically sealedconnection with internal electronics is provided, wherein saidnon-conductive substrates forms a base card body after assembly.

[0009] The individual components, in particular, the coil and the chip,are mounted on different substrates and are mounted separately from oneanother. In this manner, the features of the invention first have theresult that with an error, for example, upon mounting the chip on thecorresponding substrate, most significantly, these parts are unusable,while the separately made antenna unit, in which a substantialconstructional expense is made, is not affected by such an error. Inaddition, the features of the invention have the result that the antennaunit, comprising the second substrate and the antenna coil, can beprepared independently from the chip, so that an antenna unit forvarious chip parts, comprising the substrate and a chip mounted on thefirst substrate or countersunk thereon can be used. This is significant,since various chip parts may be different by means of the software ordifferent data used therein. The advantages of the method of the presentinvention lie in the very efficient manufacture of contactless cards. Inthat the various components are arranged on different substrates, thedifferent production steps can be performed on different equipment. Inthis manner, each type of equipment can be adapted optimally forproduction performance. The assembly of the individual substrate layerstakes place entirely at the conclusion of the assembly process,according to which, already all time-intensive process involvingcomponent-fitting are completed. An essential advantage of the methodaccording to the present invention lies in the improved rate of yield ofthe entire process, since each individual substrate can be tested on itsfunction with the associated component before complete assembly andprocessed further, if necessary. With the manufacture according to thepresent invention, on the one hand, an antenna substrate is used, whichcan be made by means of etching technology, printing technology, orwire-laying technology and which supports all antennae of the plannedapplication. On the other hand, a separate substrate is made and used,on which all chip modules of the intended application are premounted. Inthis regard, the chips are mounted onto the substrate according to theirlater position in the entire structure and fixed there. The fixing cantake place by means of adhesive. In this connection, the adhesive can beapplied either already on the substrate or on the chip module. Bycorresponding pressing-on of the chip module onto the substrate, theadhesive is activated, and if necessary, is hardened by means of theaction of heat or UF light action. The fixing of the chip module on thesecond substrate, however, alternatively can take place by means ofultrasound action. In this manner, a “rubbing in” of the chip modulesurface into the substrate takes place. If additional components areneeded in the contactless card, these can either be mounted on the samesubstrate on which the chip module is already mounted. However, withcertain embodiments, it also can be advantageous to mount the furthercomponents on further, separate substrates. In order to build the entireswitching mechanism, the individual substrates are assembled in apositionally-accurate manner and pressed with one another. The mergingof the substrates must take place, such that the contact surfaces of thecomponents are congruent with the contact surfaces of the components ofthe next substrate. The electrical contact of the components ispositively achieved with the joining and pressing of the substrates. Inthis manner, all of the contacting steps can be processed withoutadditional steps, or alternatively, after the joining, an additionalcontacting step can be performed. All three of the previously notedcontact methods can be applied. The pressing of the substrate layers, inpractice, is performed with heat and is hereby called laminating. Inthis manner, a melting of the various substrate layers takes place sothat a hermetically sealed connection with internal electronics isprovided. This connection can be further processed then already as thecard base body. Thin components are simply “sunken” into the substratelayers upon pressing and melted down. With the use of thickercomponents, in particular, of thick chip modules, however, alternativelya further substrate layer can be inserted in the structure, whereby thissubstrate layer does not support its own components, rather, merely hasrecesses. The recesses are arranged, such that the raised regions of thethick components come to rest therein. These so-called equalizing layersare formed as an individual substrate between the other substrate layersand further processes.

[0010] According to a second aspect of the invention a transponder unitor a chip card is defined, comprising a first non-conductive substrateand a second non-conductive substrate, an electronic component and anantenna, said first and said second non-conductive substrate havingessentially the same outer boundaries, whereby said electronic componentis arranged on a first non-conductive substrate serving as a componentsupport, and said antenna also is arranged on said second non-conductivesubstrate, wherein said transponder unit is produced by the correctpositional assembly of the individual substrates.

[0011] The previously described and claimed elements to be used in thesubsequent embodiments are subject to no particular excepted conditionsin regard to their size, styling, material use, and technicalconception, so that the selection criteria known in the respectiveapplication can find unlimited use. Further characteristics, features,and advantages of the subject matter of the present invention areprovided in the subsequent description of the accompanying drawings, inwhich, by way of example, a method for the present invention isexplained.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 shows the plan view of a contactless card and its internalcomponents;

[0013]FIG. 2 shows the plan view of the deployment arrangement ofcontactless cards during the manufacturing process;

[0014]FIG. 3 shows the two substrate layers during the assembly;

[0015]FIG. 4 shows the view of the joined substrates of a transponder incross section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016]FIG. 1 shows an embodiment of a contactless chip card. The outercontour 1 of the card corresponds to the standard contour for chipcards, as described in ISO Norm 7816. In the interior of the card, thechip module 2 and the antenna 3 are located.

[0017] In the illustrated embodiment, the antenna 3 is made by means ofwire-laying technology. In this manner, a wire conductor correspondingto the antenna contour is mounted on a substrate. On the point at which,upon joining the substrates, the contact surfaces of the antenna andchip module cover one another, the contact point 4 is provided. Theelectrical contact can exist purely by pressing onto one another.Alternatively, the above-described additional contact methods can beused. The thickness of the illustrated cards corresponds in practice tothe thickness of ISO cards, such as those described in ISO Norm 7816.

[0018]FIG. 2 shows the use arrangement of the individual transpondersduring the manufacture of the contactless cards. The describe substratesare not designed here for each individual card, rather arranged inlarger formats. In the industry, typical use formats are 3×8 or 6×6. Inaddition, many further different formats are provided.

[0019] The arrangement of the transponders takes place in a screen-typemanner with constant spacing in the longitudinal direction 5 and in thetransverse direction 6. For simplicity, the illustration is pictured inFIG. 2 only as a 3×3 use format. The embodiment of the individualtransponders 7 on the use is completely identical. Each individualtransponder hereby comprises a chip module 8 and an associated antenna9. For improved orientation of the individual substrates, frequentassistance lines 10 are imprinted onto the substrate in order tofacilitate the assembly. This assistance lines mark the exactintermediate space between the individual transponders on the substrate.

[0020]FIG. 3 shows the individual substrate before the assembly in theuse arrangement. Substrate 11 supports the antenna 12, whereby this isarranged exactly in the defined use arrangement and position. On theantenna substrate, assistance lines 13 can be applied, which simplifythe orientation on one another of both substrates. The antennae 12 lieon the underside of the substrates, that is, on the side facing towardthe second substrate. The second substrate 14 shows the substrate onwhich the chip modules 15 already are mounted. The chip modules arealready fixed onto the substrate by means of the previously describedmethod. The chip modules 15 lie on the top side, that is, on the side ofthe substrate facing the antennae 12.

[0021] For further processing, both substrates 11 and 14 are oriented tobe correctly position and pressed onto one another.

[0022]FIG. 4 shows the view of the joined substrates of a transponder incross section. One recognizes the lower substrate 16 on which the chipmodule 17 is arranged. Opposite is the upper substrate 20, whichsupports the antenna 19 on its underside. In the contact region 18, theantenna 19 and the contact surfaces 23 of the chip module overlap. Atthis point, the electrical connection is formed.

[0023] In this view, additionally an equalizing substrate 21 is shown.This substrate does not support any components, rather contains only anopening 22, in which the chip module 17 comes to rest after the assemblyprocess.

1. A method for producing a transponder or contactless chip card, said transponder or contactless chip comprises a first non-conductive substrate and a second non-conductive substrate, an electronic component and an antenna, said first and said second non-conductive substrate having essentially the same outer boundaries, said method comprises the steps of arranging said electronic component on said first non-conductive substrate serving as a component support, arranging said antenna on said second non-conductive substrate, and thereafter, by means of correct and accurate positional assembling the individual substrates, producing the total switching mechanism by laminating the substrate layers using heat and thereby melting of the various substrate layers so that a hermetically sealed connection with internal electronics is provided, wherein said non-conductive substrates forms a base card body after assembly.
 2. The method according to claim 1, wherein said contactless chip card comprises multiple electronic components and multiple antennae.
 3. The method according to claim 1, comprising the further step of contacting of said components assembling said substrates.
 4. The method according to claim 3, wherein said step of contacting is performed by means of auxiliary materials such as soldering or adhesive.
 5. The method according to claim 3, wherein said step of contacting is performed by means of micro-welding without auxiliary materials.
 6. The method according to claim 1, wherein in at least one of said substrates, a recess for receiving the components of the other substrate is provided.
 7. The method according to claim 1, providing a third substrate between said first substrate and said second substrate, said third having an recess for receiving the components.
 8. A transponder unit or a chip card, comprising a first non-conductive substrate and a second non-conductive substrate, an electronic component and an antenna, said first and said second non-conductive substrate having essentially the same outer boundaries, whereby said electronic component is arranged on a first non-conductive substrate serving as a component support, and said antenna also is arranged on said second non-conductive substrate, wherein said transponder unit is produced by the correct positional assembly of the individual substrates.
 9. The transponder unit according to claim 8, further comprising top layers, which are applied after the assembly of the substrate layers on the top or bottom side.
 10. The transponder unit according to claim 9, wherein at this is integrated in a further housing. 